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UNITED STATES PATENT OFFICE PACKAGE York, N. Y., a corporation of Delaware No Drawing.

Application July 28, 1931,

Serial No. 553,686

2 Claims.

This invention relates to the art of packagings and more particularly to a package wherein the wrapper exhibits and preserves the contents under refrigerating conditions.

The art of wrapping and packaging materials, such as foodstuffs, in transparent materials is well known, the purpose being to effectively display the goods without their becoming soiled, contaminated, 01' otherwise affected.

More recently it has become the practice to wrap or package these and similar materials in a transparent moisture-proof material to give all the advantages of the former method and, in addition, to prevent the gain or loss of moisture, which in the case of certain goods would make them unsatisfactory and unmarketable.

It has been found, however, that certain goods cannot well be packaged in any of these cellulose, the cellulose and/or the glycerin contained therein absorbs the moisture from the meat and sticks to the meat so that it is difficult to conveniently remove it. Moreover, the regenerated cellulose sheet is permeable to the transmission of moisture vapor so that the meat is subject to a considerable loss of its moisture, whereby its appearance and its savor are impaired.

On the other hand, when fresh or smoked meats are packaged or wrapped in moistureproof materials, such as moistureproof regenerated cellulose sheeting, it is found that these packages in a normal refrigerating condition become fogged and the contents are not visible. With the present trend for illuminated refrigerating show cases, this is a serious matter since the desideratum of the transparent wrapper and of the illuminated show case is defeated. In my opinion, there are two causes which produce this fogging.

If a cold package, wherein the wrapper consists of a moistureproof material, such as moistureproof regenerated cellulose sheeting, is subjected to warm air, moisture condenses on the outside of the film and thus fogs it. Generally this occurs when the doors of the refrigerating show cases are repeatedly opened. Under such conditions the warm moist air rushing in promptly condenses on the packages.

Conversely, if a warm package of the type previously mentioned is subjected to cold air, the moisture retained in the meat by virtue of the moistureproof regenerated cellulose sheeting condenses on the inside of the film and fogs it.

Another objection to a moistureproof wrapping is that it so effectively preserves the meat that its color remains that of a freshly cut slice instead of the color usually associated with good quality meat. It is also noticed that water, or

water and blood, sometimes form a pool within the package and become unsightly.

I have found that by wrapping meat or the like in a wrapping tissue consisting of a sheet of material, preferably a transparent material, such as ordinary regenerated cellulose sheeting, provided with a non-moistureproof lacquer coating, a package will result wherein the wrapper will not adhere to the contents and will be transparent under refrigerating conditions as well as present and preserve the contents in a satisfactory condition.

It is therefore an object of this invention to provide a package containing a substance, for example, a foodstuff such as meat, etc., which is subject to putrefaction, deterioration, or the like, enveloped in a transparent wrapper which does not stick to said substance, presents it in a satisfactory condition, and remains transparent under refrigerating conditions.

Other objects will appear from the following description and appended claims.

To achieve the above-mentioned objects, the goods are enveloped in a wrapper consisting of a sheet of material, preferably a transparent material, provided on both sides thereof with a. non-moistureproofing coating. The coating is of such a nature that it imparts to the base a surface which does not stick to the contents of the package. It permits suflicient transmission of water vapor therethrough, with the result that fogging of the wrapper by condensed moisture when the package is handled or disposed in a refrigerating or other atmosphere is prevented or materially inhibited. The rate of moisture transmission is, however, not so great that the quality of the material wrapped is reduced by a loss in moisture. This is probably due to the fact that the ingress and egress of moisture under the refrigerating conditions approach a balance.

As the base, I prefer to use sheets or films of regenerated cellulose, since these provide a glass-clear transparency, as well as being very satisfactory in strength. Alternately, I may use sheets or films of gelatine hardened or not as desired. I may, moreover, for many purposes, where a high degree of transparency is not required and where cost becomes an important item, use as a base a material, such as glassine paper, tissue paper or chemically treated paper, in which case, by the proper choice of a coating lacquer, I can provide the necessary surface and materially improve the normal transparency thereof.

As the coating composition, I prefer to use any of the lacquers which deposit a transparent, non-tacky, flexible and water-insoluble film. For example, I may use a lacquer containing a cellulose derivative, either an ester,

such as acetate, nitrate, formate, etc., or an ether, such as ethyl cellulose or the like, one or more resins or gums of the natural or synthetic variety or mixtures thereof with or without plasticizers or softeners. I may also very well use a lacquer containing a synthetic resin or even a soft natural resin and a plasticizer dissolved in suitable solvents. Lacquers, containing quick-drying oils, together with gums or resins and softeners, although a little slow in setting, have also been found to be very satisfactory.

These lacquers and the films produced therefrom are sharply differentiated from those described in the Chareh et al. Patent 1,737,187 by the fact that my films or the papers so coated are not moistureproof as the word is used therein. They are further differentiated by the fact that they do not in their preferred forms contain any wax or waxlike materials, although in special cases I may elect to incorporate a very small amount of wax and particularly a kind of wax or waxlike material which is known to contribute but very little moistureproofness.

In order to more clearly explain the coating compositions, I shall hereafter present several specific examples of lacquers which are satisfactory for my purpose, it being understood that these are illustrative and not restrictive:

Example I Percent Nitrocellulose 5.0 Gum dammar 3.0 Tricresyl phosphate 2.5 BTityI' acetate 5.0 Ethyl acetate 42.0 Ethyl alcohol 2.5 Tuluol 40.0

Example II Percent Cellulose acetate 4.0 Gum elemi 2.5 Ethyl para toluol sulphamid resin 2.0 Acetone 25. 5 Ethyl lactate 22.0 Toluol 44. 0

Example III Parts Chinawood oil 783 Litharge 30 East India gum 500 Calcium stearate Turpentine substitute 1,400

- Example IV Parts Linseed oil 150 Cobalt linoleate 2.5 Glyptal resin 100 Toluene 250 Additional solvents may be added to suit the consistency desired.

* The glyptal resin is made from the follow- Example V Parts Polymerization product resulting from vinyl chloride 60% and vinyl acetate 40% Tricresyl phosphate 7 Toluene 100-200 The base may be treated with the lacquer in any convenient manner, such as by dipping, spraying, coating, etc., and the solvents will subsequently be removed at either atmospheric temperature or at elevated temperatures, depending on the solvents used and the purpose in hand. In one specific method the sheets or films may be run through the lacquer bath, excess scraped therefrom, and the solvent removed by evaporation in a tower. In the case of regenerated cellulose, and to some extent even paper, it will be found well to subject the coated and dried sheet or film to a warm humidifying atmosphere in order to restore the flexibility by reintroducing the moisture that may have been lost in the coating process. This treatment will also serve the useful purpose of removing the last traces of solvent, which would impart an undesirable odor to the material.

While I have discussed fresh and smoked meats as examples of the materials, the packaging of which is contemplated by this invention, I do not desire to be limited to these. I have found that other materials are very satisfactorily packaged or wrapped in my material. For example, it is also admirably suitable for wrapping certain foodstuffs, of which doughnuts are familiar examples, and which dry out if not protected and become soggy if too well protected with regard to transmission of moisture. Likewise, it is equally applicable for wrapping substances containing moisture or hydroscopic substances especially when it is desired that the package be transparent and free from turbidity and fogginess.

The wrapping tissue, instead of comprising a suitable base coated with lacquers of the type hereinbefore described, may consist only of films or sheeting formed of said compositions.

Since it is obvious that various changes and modifications may be made in the invention above set forth without departing from the spirit thereof, this invention is not restricted to the specific details described except as defined in the appended claims.

I claim:

1. A package comprising meat enveloped in a transparent flexible wrapper which does not stick to said meat and remains transparent under refrigerating condition, said wrapper comprising a sheet or film of a cellulose base coated with a non-moistureproofing lacquer.

2. A package comprising meat enveloped in a transparent flexible wrapper which does not stick to said meat and remains transparent under refrigerating condition, said wrapper comprising a sheet or film of regenerated cellulose coated with a non-moistureproofing lacquer.

JULIUS DUNCAN RANKIN. 

